$$PQR$$ is a triangle, whose area is 180 $$cm^2$$. $$S$$ is a point on side $$QR$$, such that $$PS$$ is the angle bisector of $$\angle QPR$$. If $$PQ : PR = 2 : 3$$, then what is the area (in $$cm^2$$) triangle $$PSR$$?

A

90

B

108

C

144

D

72